2-octanol extraction

EXTRACTION INTO OCTANOL EXTRACTION INTO OCTANOL... 

Gluco amylase Aspergillus awamori TOMAC/Revopal HV5/n-octanol/ Extraction [57,58]... 

Trichloroacetic acid-octanol extraction AA oxidized to DHAA using ascorbic acid oxidase total vitamin C as DHAA derivatized with o-phenyl-diamide... 

CiC imPp6 n = A, 6, 8) (Pig. 6). It was also quoted that the acid dependencies of Dsi in CiC2imTf2N using HCl or H2SO4 differ little from the one observed with HNO3 (Dietz and Dzielawa, 2001). Finally, EXAFS data acquired in several extracted IL phases (CiC imTf2N, n = 5,6, 8, 10) could not evidence any nitrate ions in the first Sr " " coordination sphere, while two nitrates are detected in 1-octanol extraction phase (Dietz et al., 2003). Unfortunately, no indication on the nitric acid concentration at which the EXAFS data have been recorded is given in this paper. 

Strkcttire inflkence. The specificity of interphase transfer in the micellar-extraction systems is the independent and cooperative influence of the substrate molecular structure - the first-order molecular connectivity indexes) and hydrophobicity (log P - the distribution coefficient value in the water-octanole system) on its distribution between the water and the surfactant-rich phases. The possibility of substrates distribution and their D-values prediction in the cloud point extraction systems using regressions, which consider the log P and values was shown. Here the specificity of the micellar extraction is determined by the appearance of the host-guest phenomenon at molecular level and the high level of stmctural organization of the micellar phase itself. 

On the basis of data obtained the possibility of substrates distribution and their D-values prediction using the regressions which consider the hydrophobicity and stmcture of amines was investigated. The hydrophobicity of amines was estimated by the distribution coefficient value in the water-octanole system (Ig P). The molecular structure of aromatic amines was characterized by the first-order molecular connectivity indexes ( x)- H was shown the independent and cooperative influence of the Ig P and parameters of amines on their distribution. Evidently, this fact demonstrates the host-guest phenomenon which is inherent to the organized media. The obtained in the research data were used for optimization of the conditions of micellar-extraction preconcentrating of metal ions with amines into the NS-rich phase with the following determination by atomic-absorption method. 

A solution of 50 g of 1 -azabicyclo[2.2.2] -3-octanol hydrochloride in 30 cc water was made alkaline with 30 g of potassium hydroxide. After the alkali was dissolved 35 g of granular potassium carbonate were added. The free basic alcohol was then extracted from the viscous mixture by shaking with four portions of boiling benzene (300 cc in each portion). The benzene extracts were decanted and filtered over anhydrous sodium sulfate, to remove any suspended alkali. The combined benzene solutions were concentrated in vacuo. The residue was recrystallized from benzene and identified as 1 -azabicyclo[2.2.2] -3-octanol, MP 221°-223°C. The product can also be purified by recrystallization from acetone, or by sublimation in vacuo (120°C/20 mm Hg). The alcohol was reacted with acetic anhydride to give the product ace-clidine. 

Fig. 5-12. Separation of d,1-leucine in hollow-fiber membrane extraction using a Al- -dodecyl-l-hydrox-yproline solution in octanol as the enantioselective extraction liquid. The modules used were 32 cm long and contained 96 Celgard X-20 polypropylene fibers [57].

Alcohols with a C8 - Cn chain length, characterized by low solubility in aqueous media, may have a particular commercial potential as perspective extractants for tantalum and niobium hydrometallurgical processing. Particular emphasis has been placed recently on the investigation of tantalum and niobium extraction using octanol (C8Hi80) in the forms of 1-octanol and 2-octanol [462,466-473]. 

Extraction of tantalum and niobium with 2-octanol -definition of the process parameters... 

Comprehensive comparative investigation of the main extraction parameters shows that 2-octanol is more selective than 1-octanol, with PTa/m equal to... 

The optimal parameters of tantalum extraction with 2-octanol are as follows ... 

Fig. 133. Isotherm of distribution of niobium between organic and aqueous phases during extraction by 2-octanol from initial solution containing 6 M H2SO4 (after Agulyansky et al, [473]).

Table 62. Typical purity of tantalum and niobium oxides prepared from strip solutions after extraction with 2-octanol. Impurity level is given in ppm.

Table 63. Optimal parameters of tantalum and niobium extraction with 2-octanol.

Layered-type structure, 92-100 Lewis acidity, 15 Liquid - liquid extraction collective, 276-277 counter-current scheme, 272 equipment, 273 extractants, 279-281 mechanism, 274-276 multistage counter-current, 271 multistage cross-current, 270 one-stage process, 270 principals, 267-269 process performance, 282-283 process schemes, 277,278, selective, 277-278 with 2-octanol, 284-291... 

Using a solution of water-containing reversed micelles of di(2-ethylhexyl)phospho-rothioic acid in isooctane, hemoglobin was extracted and concentrated. Desolubilization of the protein entrapped in the reversed micelles by weak alkahne solution was realized by adding small amounts of n-octanol [167]. 

Along the same lines it was advocated that colors be read at the absorption maximum rather than at some other convenient point. An example of this is the increase in absorbance one obtains when analyzing for bromide by means of gold chloride (18). As can be seen from Figure 14, the peak with gold bromide increases by a factor of more than 2 when the color is extracted into octanol and read at its absorption maximum (18). 

Such ion-pair constants are conditional , in that they depend on the concentration of the counterion with which the charged drug molecule enters into the octanol phase as an ion-pair. This is due to the low dielectric property of octanol, inducing charge neutrality upon uptake of charged drug molecules. Extraction constants may be used to explicitly include the participahon of the counterion [18]. 

The following physico-chemical properties of the analyte(s) are important in method development considerations vapor pressure, ultraviolet (UV) absorption spectrum, solubility in water and in solvents, dissociation constant(s), n-octanol/water partition coefficient, stability vs hydrolysis and possible thermal, photo- or chemical degradation. These valuable data enable the analytical chemist to develop the most promising analytical approach, drawing from the literature and from his or her experience with related analytical problems, as exemplified below. Gas chromatography (GC) methods, for example, require a measurable vapor pressure and a certain thermal stability as the analytes move as vaporized molecules within the mobile phase. On the other hand, compounds that have a high vapor pressure will require careful extract concentration by evaporation of volatile solvents. 

Water solubility, dissociation constant(s) and n-octanol/water partition coefficients allow one to predict how an analyte may behave on normal-phase (NP), reversed-phase (RP), or ion-exchange solid-phase extraction (SPE) for sample enrichment and cleanup. 

In almost all theoretical studies of AGf , it is postulated or tacitly understood that when an ion is transferred across the 0/W interface, it strips off solvated molecules completely, and hence the crystal ionic radius is usually employed for the calculation of AGfr°. Although Abraham and Liszi [17], in considering the transfer between mutually saturated solvents, were aware of the effects of hydration of ions in organic solvents in which water is quite soluble (e.g., 1-octanol, 1-pentanol, and methylisobutyl ketone), they concluded that in solvents such as NB andl,2-DCE, the solubility of water is rather small and most ions in the water-saturated solvent exist as unhydrated entities. However, even a water-immiscible organic solvent such as NB dissolves a considerable amount of water (e.g., ca. 170mM H2O in NB). In such a medium, hydrophilic ions such as Li, Na, Ca, Ba, CH, and Br are selectively solvated by water. This phenomenon has become apparent since at least 1968 by solvent extraction studies with the Karl-Fischer method [35 5]. Rais et al. [35] and Iwachido and coworkers [36-39] determined hydration numbers, i.e., the number of coextracted water molecules, for alkali and alkaline earth metal... 

A comprehensive study of the complex interfacial processes involved in the solvent extraction of cupric ion by oxime ligands represents one of the most detailed and successful studies carried out with the RDC [37,38]. Recently, the technique was also used to study the transfer of tetrabutylammonium cations [43] and the kinetics of partitioning of compounds between octanol and water [44]. In the latter study, Fisk and coworkers investigated the rates of partitioning of 23 compounds from octanol to an aqueous phase. The RDC arrangement used most frequently in this work is of the o/o/w type. So according to Eq. (15), and can be calculated from the gradient and intercept of... 

SREX [Strontium extraction] A process for removing strontium-90 from aqueous wastes from nuclear fuel processing, by solvent extraction into a solution of 18-crown-6 in octanol. Developed by E. P. Horwitz at the Argonne National Laboratory, Chicago, IL, in 1990. 

Several investigators have described the indirect determination of orthophosphate by extraction of the phosphomolybdic acid complex and the measuring the molybdenum extracted. Zaugg and Knox 2921 first applied this technique to the determination of phosphate in urine. A protein-free filtrate was formed and the complex was extracted into 2-octanol. More recently, Devoto 293) determined 0 to 25 pg of phosphate in 50 ml of urine by extracting the complex from acidified urine into isobutyl acetate. 

Several manufacturers introduced products amenable for this solid-supported LLE and for supported liquid extraction (SLE). The most common support material is high-purity diatomaceous earth. Table 1.8 lists some commercial products and their suppliers. The most widely investigated membrane-based format is the supported liquid membrane (SLM) on a polymeric (usually polypropylene) porous hollow fiber. The tubular polypropylene fiber (short length, 5 to 10 cm) is dipped into an organic solvent such as nitrophenyl octylether or 1-octanol so that the liquid diffuses into the pores on the fiber wall. This liquid serves as the extraction solvent when the coated fiber is dipped... 

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